Halohydrins

General structure of halohydrins - X = I, Br, F, or Cl

Structure of the halohydrin 2-chloroethanol

Halohydrins are a class of organic compounds that have a halogen as a substituent on a carbon atom as a functional group and a hydroxyl group on an adjacent carbon atom .

They are usually made from olefins by halogenation in the presence of water. N -Bromosuccinimide (NBS) or N -chlorosuccinimide (NCS) is often used as the halogen source . Another process is the reaction of epoxides with hydrogen halide acids.

In the presence of a base, the halohydrin is only formed as an intermediate and an intramolecular cyclization to the epoxide takes place. This is the reverse of the reaction to produce halohydrins from epoxides with hydrohalic acids .

Epoxidations in biological systems can be catalyzed by halohydrin halogenases .

literature

• Organikum , 16th edition, VEB Deutscher Verlag der Wissenschaften Berlin 1985, ISBN 3-326-00076-6 , p. 254.